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目的:比较恶性疟原虫不同分离株组氨酸富集蛋白II( HRPII)基因全编码区核苷酸序列。方法: PCR扩增恶性疟原虫海南株(FCC1/HN)和越南株(VN)的HRPII基因全编码区, 其产物经HindIII和Bam HI双酶切,定向克隆入pUC19, 采用Sanger 双脱氧链末端终止法测序。结果:FCC1/HN 株和VN 株HRPII基因均为1 020bp, 无内含子, 两者仅10 个碱基不同。FCC1/HN 株HRPII与VN 株、IMTM22 株和Itg2 株间氨基酸同源性分别为98.8% 、92.2% 和98.7% ; 4 株虫体均有拷贝数不等的丙氨酸-组氨酸-组氨酸(AHH)和丙氨酸-组氨酸-组氨酸-丙氨酸-丙氨酸-天冬氨酸(AHHAAD) 重复序列, 具有相同的信号肽和糖基化位点。4 个分离株HRPII抗原表位相同,位于易曲性较高的5端非AHH 和AHHAAD 重复区。结论: FCC1/HN 株与VN 株的HRPII高度同源,与IMTM22 株和Itg2 株存在序列差异
Objective: To compare the nucleotide sequence of the complete coding region of histidine-rich protein II (HRPII) in different isolates of Plasmodium falciparum. Methods: The complete coding region of HRPII gene of Plasmodium falciparum (FCC1 / HN) and Vietnam strain (VN) was amplified by PCR. The product was double digested with HindIII and Bam HI and cloned into pUC19. Termination method sequencing. Results: The HRPII genes of FCC1 / HN strain and VN strain were all 1 020 bp with no introns, and the two genes were only 10 bases different. The homology of amino acids between FCC1 / HN strain HRPII and VN strain, IMTM22 strain and Itg2 strain were 98.8%, 92.2% and 98.7%, respectively. The four strains had alanine-histidine- (AHH) and alanine-histidine-histidine-alanine-alanine-aspartate (AHHAAD) repeats with the same signal peptide and glycosylation sites. The four HRPII epitopes of the isolates were the same, located at the 5 non-AHH and AHHAAD repeats with high susceptibility. CONCLUSION: The HRPII of FCC1 / HN strain and VN strain are highly homologous with the sequences of IMTM22 strain and Itg2 strain